Research on Normal Contact Stiffness of Rough Joint Surfaces Machined by Turning and Grinding

Abstract

In order to accurately obtain the contact stiffness of rough joint surfaces machined by turning and grinding, a research simulation is carried out by using the finite element method. Based on the surface modeling method under the combined machining mode, the three-dimensional (3D) solid model is constructed. Then, the finite element results of the normal contact stiffness were obtained through contact analysis. The comparative analysis was carried out with the analytical results of the KE model and the experimental results. The comparison results show that three results have the same trend of change. However, the maximum relative error of the finite element results is 6.03%, while that of the analytical results for the KE model is 60.07%. After that, the finite element results under different machining parameters are compared. The normal contact stiffness increases with the increase in the turning tool arc radius, grinding depth, and fractal dimension, but decreases with the increase in the turning feed rate and scale coefficient. The rationality of the results is explained by the distribution of the asperities and the contact deformation law of the asperities on the rough surface.